The pituitary gland, a pea-sized gland, is located inside the skull just below the brain and above the nasal passages. It is responsible for helping to regulate the functions of other endocrine glands such as the thyroid gland, adrenal glands, ovaries, and testes. A pituitary disorder, or tumor, can significantly affect your quality of life because of the pituitary’s role in regulating some of these other endocrine glands.
Pituitary tumors, or pituitary lesions, are the most common cause of pituitary gland disorders and are benign most of the time. Only a small percentage of pituitary tumors are cancer.
The pituitary gland has two parts: the anterior pituitary and the posterior pituitary, each with distinct functions. Most pituitary tumors are known as non-functioning adenomas and do not produce excessive amounts of hormones, while others can result in hormone overproduction, causing serious endocrine problems, such as acromegaly (GH excess), Cushing's syndrome (ACTH excess) or prolactinoma (prolactin excess).
Small pituitary adenomas are called microadenomas, while larger tumors are called macroadenomas. As pituitary tumors grow, they can compress the pituitary gland and cause decreased hormone production. The tumors can also compress the optic nerve which can lead to visual problems and headaches.
Types of Pituitary Tumors
- Growth hormone: Acromegaly is a rare disease typically caused by a noncancerous tumor in the pituitary gland. Acromegaly is caused by the excess secretion of growth hormone (GH). This condition often requires surgery as the first line of treatment.
- Cushing’s syndrome/ACTH (Adrenocorticotropic hormone): Cushing's syndrome is caused when the pituitary gland produces too much adrenocorticotropic hormone. A pituitary tumor can cause this condition. Surgery is most commonly the first line of treatment.
- Prolactinoma: A prolactinoma is the most common secretory tumor. This tumor produces too much prolactin, the hormone that causes milk production. It can be treated with a medication.
- Non-secreting tumors: Non-secreting tumors do not secrete hormones but can cause health problems because of their size and location. These types of tumors are treated surgically if causing visual symptoms.
- Pituitary cancer: In rare cases, a pituitary tumor can become cancer and metastasize (spread) to other areas of the body.